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Topic: Fly Sparging (Read 8603 times)

There can be layer that forms on top of the mash called "teig" which is the German word for dough. That stuff is fine and makes a dense almost impermeable layer.

You can read about knifing the mash in Gordon Strong's article about the homebrewers at SN Beer Camp. He covers what Scott Jennings said on the homebrew scale, and that one of the homebrewers went back and reported an efficiency increase (Jan-Feb 2010 Zymurgy). That rang a bell with me, as one Larry Bell (pun intended) had talked about how one of the mash tuns got higher efficiency as it had knives, the other didn't back in the later 90s when they had 2 brewhouses in Kalamazoo.

I mash with RIMS and the flow rate through the bed during mashing is far higher than when I'm running off. I've never seen a layer of anything on my mashes. I wonder why regular mashes present this. Do most brewers have this layer on their mash?

I get it consistently for my weizen, which is 60% wheat and single decocted. Not for any of my other beers, but then those don't have that much wheat and are not decocted.

I get the thin layer on top of my mash, for sure. It is like a thin layer of damp flour. I stir my mash for a good long time at mash in and have always just assumed that it suspended the lightest particulate matter to the top. I have never cut it, because I simply batch sparge (stirring again after adding the sparge water for the second run).

I know that people often refer to this Oberteig as "flour", but it is mostly proteins, polyphenols, beta glucans, lipids and the like that have precipitated out during the mash. Essentially this is your mash break, which is probably a sign of good pH and calcium concentration.

The risk to channeling is probably that it can lead to flow around the outside of the grain bed having less resistance than through the grain bed. That could lead to reduced efficiency and over sparging during a fly sparge.

I've cut it before, but always followed that with a second Vorlauf. A good quantity of whole husks should prevent this from being a problem, though, for most mashes.

Given their quality control, I can see how maximizing efficiency would be an advantage to a professional brewer in a professional brewery. For the homebrewer, I've had numerous very experienced brewers tell me not to shoot for it as you run the risk of over sparging and extracting tannins.

To each their own, but I think comparing even a very experienced home brewer to Sierra Nevada is a major stretch......if we could all brew like Sierra Nevada, there would not be a Sierra Nevada.

Given their quality control, I can see how maximizing efficiency would be an advantage to a professional brewer in a professional brewery. For the homebrewer, I've had numerous very experienced brewers tell me not to shoot for it as you run the risk of over sparging and extracting tannins.

To each their own, but I think comparing even a very experienced home brewer to Sierra Nevada is a major stretch......if we could all brew like Sierra Nevada, there would not be a Sierra Nevada.

Dave

Yeah, I agree with you...I seldom compare commercial operations to homebrewers. But my point was that high efficiency doesn't necessarily cause problems. My average efficiency runs about 85% and I sometimes get up into the 90s. I don't get astringency from tannins because of it. Taking advice from experienced brewers is a great thing, but you should always check it our for yourself.

Given their quality control, I can see how maximizing efficiency would be an advantage to a professional brewer in a professional brewery. For the homebrewer, I've had numerous very experienced brewers tell me not to shoot for it as you run the risk of over sparging and extracting tannins.

To each their own, but I think comparing even a very experienced home brewer to Sierra Nevada is a major stretch......if we could all brew like Sierra Nevada, there would not be a Sierra Nevada.

Dave

Yeah, I agree with you...I seldom compare commercial operations to homebrewers. But my point was that high efficiency doesn't necessarily cause problems. My average efficiency runs about 85% and I sometimes get up into the 90s. I don't get astringency from tannins because of it. Taking advice from experienced brewers is a great thing, but you should always check it our for yourself.

Sierra Nevada has a mill with large rollers that shears the grains and leaves the husk mostly intact. They also have 5.5 ph water throughout the brewery. With that pH the tannin extraction will be minimal.

Edit - the brewers that hammer mill the grains and have a mash press get >100% efficiency.

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Jeff RankertAnn Arbor Brewers GuildAHA Governing Committee BJCP NationalHome-brewing, not just a hobby, it is a lifestyle!

Good info Jeff. How is it that you can get >100%? What makes up the calcs?

I also can see that if the process is sound, the PH correct and sparge water at the right temps, there is nothing wrong with over 85% efficiency. I dialed mine back on some advice when I was getting 85%+ every batch, but I do not remember ever getting any astringency. Sparge on if you like it that way!

I do like my consistent 80% and cutting the brew day down 30+ minutes though.....

Good info Jeff. How is it that you can get >100%? What makes up the calcs?

I also can see that if the process is sound, the PH correct and sparge water at the right temps, there is nothing wrong with over 85% efficiency. I dialed mine back on some advice when I was getting 85%+ every batch, but I do not remember ever getting any astringency. Sparge on if you like it that way!

I do like my consistent 80% and cutting the brew day down 30+ minutes though.....

Dave

The Congress mash is the referrence. Milled to a fine flour, mashed in distilled water, drained through a filter IIRC, feel free to correct this if you know more.

The hammer mill get it very fine, and the mash press squeezes the mash between the filter plates that give a large area. They get it all out through pressing the mash, so they can exceed the Congress mash.

These are popular in Belgium. I have talked to local brewers that would love to have one, and there is a new place going up that has one ordered for the system.

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Jeff RankertAnn Arbor Brewers GuildAHA Governing Committee BJCP NationalHome-brewing, not just a hobby, it is a lifestyle!